To test the prestack slant stack migration algorithm, a marine dataset from the Gulf of Mexico was migrated by the same processing procedures. The record length is 4 seconds and the sampling rate is 8 milliseconds. The offset interval is 50 meters and the far offset is 2591 meters. I used 100 48-fold CMP gathers with a 25-meter CMP interval. The strong events between 2.1 and 2.5 seconds which was the target of the AVO analysis the next section describes.
Velocity analyses were done at CMP 1 and CMP 100. To migrate this dataset, I needed to consider the velocity variations in depth and in lateral variation. I used prestack slant stack migration with PSPI to migrate these field data. In the slant stack transformation, I chose the p range from 0 to -0.36 Kilometer per second to fulfill the requirements of the AVO analysis that are explained in the next section.
The CMP stack section and the migrated section are shown separately in Figures 6 and 7. Some collapsed diffractions and faults (at 1 second from 0.2 to 2.0 Kilometers) are apparent after migration.